// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
#define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_

#include <atlbase.h>
#include <atlcom.h>
#include <oleacc.h>

#include "third_party/iaccessible2/ia2_api_all.h"
#include "ui/accessibility/platform/ax_platform_node_base.h"

namespace ui {

class __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2"))
    AXPlatformNodeWin
    : public CComObjectRootEx<CComMultiThreadModel>,
      public IDispatchImpl<IAccessible2_2, &IID_IAccessible2,
          &LIBID_IAccessible2Lib>,
      public IAccessibleText,
      public IServiceProvider,
      public AXPlatformNodeBase {
public:
    BEGIN_COM_MAP(AXPlatformNodeWin)
    COM_INTERFACE_ENTRY2(IDispatch, IAccessible2_2)
    COM_INTERFACE_ENTRY(AXPlatformNodeWin)
    COM_INTERFACE_ENTRY(IAccessible)
    COM_INTERFACE_ENTRY(IAccessible2)
    COM_INTERFACE_ENTRY(IAccessible2_2)
    COM_INTERFACE_ENTRY(IAccessibleText)
    COM_INTERFACE_ENTRY(IServiceProvider)
    END_COM_MAP()

    ~AXPlatformNodeWin() override;

    // AXPlatformNode overrides.
    void Destroy() override;
    gfx::NativeViewAccessible GetNativeViewAccessible() override;
    void NotifyAccessibilityEvent(ui::AXEvent event_type) override;

    // AXPlatformNodeBase overrides.
    int GetIndexInParent() override;

    //
    // IAccessible methods.
    //

    // Retrieves the child element or child object at a given point on the screen.
    STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child) override;

    // Performs the object's default action.
    STDMETHODIMP accDoDefaultAction(VARIANT var_id) override;

    // Retrieves the specified object's current screen location.
    STDMETHODIMP accLocation(LONG* x_left,
        LONG* y_top,
        LONG* width,
        LONG* height,
        VARIANT var_id) override;

    // Traverses to another UI element and retrieves the object.
    STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end) override;

    // Retrieves an IDispatch interface pointer for the specified child.
    STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child) override;

    // Retrieves the number of accessible children.
    STDMETHODIMP get_accChildCount(LONG* child_count) override;

    // Retrieves a string that describes the object's default action.
    STDMETHODIMP get_accDefaultAction(VARIANT var_id,
        BSTR* default_action) override;

    // Retrieves the tooltip description.
    STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc) override;

    // Retrieves the object that has the keyboard focus.
    STDMETHODIMP get_accFocus(VARIANT* focus_child) override;

    // Retrieves the specified object's shortcut.
    STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id,
        BSTR* access_key) override;

    // Retrieves the name of the specified object.
    STDMETHODIMP get_accName(VARIANT var_id, BSTR* name) override;

    // Retrieves the IDispatch interface of the object's parent.
    STDMETHODIMP get_accParent(IDispatch** disp_parent) override;

    // Retrieves information describing the role of the specified object.
    STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role) override;

    // Retrieves the current state of the specified object.
    STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state) override;

    // Gets the help string for the specified object.
    STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help) override;

    // Retrieve or set the string value associated with the specified object.
    // Setting the value is not typically used by screen readers, but it's
    // used frequently by automation software.
    STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value) override;
    STDMETHODIMP put_accValue(VARIANT var_id, BSTR new_value) override;

    // IAccessible methods not implemented.
    STDMETHODIMP get_accSelection(VARIANT* selected) override;
    STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id) override;
    STDMETHODIMP get_accHelpTopic(BSTR* help_file,
        VARIANT var_id,
        LONG* topic_id) override;
    STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name) override;

    //
    // IAccessible2 methods.
    //

    STDMETHODIMP role(LONG* role) override;

    STDMETHODIMP get_states(AccessibleStates* states) override;

    STDMETHODIMP get_uniqueID(LONG* unique_id) override;

    STDMETHODIMP get_windowHandle(HWND* window_handle) override;

    STDMETHODIMP get_relationTargetsOfType(BSTR type,
        long max_targets,
        IUnknown*** targets,
        long* n_targets) override;

    STDMETHODIMP get_attributes(BSTR* attributes) override;

    STDMETHODIMP get_indexInParent(LONG* index_in_parent) override;

    //
    // IAccessible2 methods not implemented.
    //

    STDMETHODIMP get_attribute(BSTR name, VARIANT* attribute) override;
    STDMETHODIMP get_extendedRole(BSTR* extended_role) override;
    STDMETHODIMP get_nRelations(LONG* n_relations) override;
    STDMETHODIMP get_relation(LONG relation_index,
        IAccessibleRelation** relation) override;
    STDMETHODIMP get_relations(LONG max_relations,
        IAccessibleRelation** relations,
        LONG* n_relations) override;
    STDMETHODIMP scrollTo(enum IA2ScrollType scroll_type) override;
    STDMETHODIMP scrollToPoint(enum IA2CoordinateType coordinate_type,
        LONG x,
        LONG y) override;
    STDMETHODIMP get_groupPosition(LONG* group_level,
        LONG* similar_items_in_group,
        LONG* position_in_group) override;
    STDMETHODIMP get_localizedExtendedRole(
        BSTR* localized_extended_role) override;
    STDMETHODIMP get_nExtendedStates(LONG* n_extended_states) override;
    STDMETHODIMP get_extendedStates(LONG max_extended_states,
        BSTR** extended_states,
        LONG* n_extended_states) override;
    STDMETHODIMP get_localizedExtendedStates(
        LONG max_localized_extended_states,
        BSTR** localized_extended_states,
        LONG* n_localized_extended_states) override;
    STDMETHODIMP get_locale(IA2Locale* locale) override;
    STDMETHODIMP get_accessibleWithCaret(IUnknown** accessible,
        long* caret_offset) override;

    //
    // IAccessibleText methods.
    //

    STDMETHODIMP get_nCharacters(LONG* n_characters) override;

    STDMETHODIMP get_caretOffset(LONG* offset) override;

    STDMETHODIMP get_nSelections(LONG* n_selections) override;

    STDMETHODIMP get_selection(LONG selection_index,
        LONG* start_offset,
        LONG* end_offset) override;

    STDMETHODIMP get_text(LONG start_offset,
        LONG end_offset,
        BSTR* text) override;

    STDMETHODIMP get_textAtOffset(LONG offset,
        enum IA2TextBoundaryType boundary_type,
        LONG* start_offset,
        LONG* end_offset,
        BSTR* text) override;

    STDMETHODIMP get_textBeforeOffset(LONG offset,
        enum IA2TextBoundaryType boundary_type,
        LONG* start_offset,
        LONG* end_offset,
        BSTR* text) override;

    STDMETHODIMP get_textAfterOffset(LONG offset,
        enum IA2TextBoundaryType boundary_type,
        LONG* start_offset,
        LONG* end_offset,
        BSTR* text) override;

    STDMETHODIMP get_offsetAtPoint(LONG x,
        LONG y,
        enum IA2CoordinateType coord_type,
        LONG* offset) override;

    //
    // IAccessibleText methods not implemented.
    //

    STDMETHODIMP get_newText(IA2TextSegment* new_text) override;
    STDMETHODIMP get_oldText(IA2TextSegment* old_text) override;
    STDMETHODIMP addSelection(LONG start_offset, LONG end_offset) override;
    STDMETHODIMP get_attributes(LONG offset,
        LONG* start_offset,
        LONG* end_offset,
        BSTR* text_attributes) override;
    STDMETHODIMP get_characterExtents(LONG offset,
        enum IA2CoordinateType coord_type,
        LONG* x,
        LONG* y,
        LONG* width,
        LONG* height) override;
    STDMETHODIMP removeSelection(LONG selection_index) override;
    STDMETHODIMP setCaretOffset(LONG offset) override;
    STDMETHODIMP setSelection(LONG selection_index,
        LONG start_offset,
        LONG end_offset) override;
    STDMETHODIMP scrollSubstringTo(LONG start_index,
        LONG end_index,
        enum IA2ScrollType scroll_type) override;
    STDMETHODIMP scrollSubstringToPoint(LONG start_index,
        LONG end_index,
        enum IA2CoordinateType coordinate_type,
        LONG x,
        LONG y) override;

    //
    // IServiceProvider methods.
    //

    STDMETHODIMP QueryService(REFGUID guidService,
        REFIID riid,
        void** object) override;

protected:
    AXPlatformNodeWin();

private:
    bool IsValidId(const VARIANT& child) const;
    int MSAARole();
    int MSAAState();
    int MSAAEvent(ui::AXEvent event);

    HRESULT GetStringAttributeAsBstr(
        ui::AXStringAttribute attribute,
        BSTR* value_bstr) const;

    void AddAlertTarget();
    void RemoveAlertTarget();

    // Return the text to use for IAccessibleText.
    base::string16 TextForIAccessibleText();

    // If offset is a member of IA2TextSpecialOffsets this function updates the
    // value of offset and returns, otherwise offset remains unchanged.
    void HandleSpecialTextOffset(const base::string16& text, LONG* offset);

    // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType.
    ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type);

    // Search forwards (direction == 1) or backwards (direction == -1)
    // from the given offset until the given boundary is found, and
    // return the offset of that boundary.
    LONG FindBoundary(const base::string16& text,
        IA2TextBoundaryType ia2_boundary,
        LONG start_offset,
        ui::TextBoundaryDirection direction);

    // A windows-specific unique ID for this object. It's returned in
    // IAccessible2::get_uniqueID, but more importantly it's used for
    // firing events. On Windows, we fire events on the nearest parent HWND
    // and pass the unique ID as the child id parameter. When the client
    // wants to retrieve the object the event was fired on, it calls
    // get_accChild and passes the child ID. We use negative IDs for the unique
    // ID so we can distinguish a request for an arbitrary child from a request
    // for an immediate child of an object by its 0-based index.
    LONG unique_id_win_;
};

} // namespace ui

#endif // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
